TypeScript/tests/baselines/reference/interfaceWithOptionalProperty.types

=== tests/cases/compiler/interfaceWithOptionalProperty.ts ===

interface I {
>I : I, Symbol(I,Decl(interfaceWithOptionalProperty.ts,0,0))

    x?: number;
>x : number, Symbol(x,Decl(interfaceWithOptionalProperty.ts,1,13))
}